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From "Xuefu Zhang (JIRA)" <>
Subject [jira] [Commented] (HIVE-8042) Optionally allow move tasks to run in parallel
Date Wed, 10 Sep 2014 19:41:33 GMT


Xuefu Zhang commented on HIVE-8042:

This seems certainly nice to have. However, I'm wondering why we need a flag for this rather
just taking hive.exec.parallel? If the dependency is set correctly, I don't see any harm of
running move task in parallel. If we have a flag for each task type, it seems the number of
options are exploding.

> Optionally allow move tasks to run in parallel
> ----------------------------------------------
>                 Key: HIVE-8042
>                 URL:
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Gunther Hagleitner
>            Assignee: Gunther Hagleitner
>         Attachments: HIVE-8042.1.patch
> hive.exec.parallel allows one to run different stages of a query in parallel. However
that applies only to map-reduce tasks. When using large multi insert queries there are many
MoveTasks that are all executed in sequence on the client. There's no real reason for that
- they could be run in parallel as well (i.e.: the stage graph captures the dependencies and
knows which tasks can happen in parallel)
> Proposal here is to create a new config var:
> hive.exec.parallel.movetask
> When set to true it run movetasks in parallel also.

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